NACA Animal Control Officers Practice Test

What is the primary method of digestion in colon fermenters?

1. Fermentation of fiber in the stomach

2. Fermentation of fiber in an enlarged colon

3. Direct absorption of nutrients in the small intestine

4. Digestion using enzymes in the cecum

The correct answer is: Fermentation of fiber in an enlarged colon

In colon fermenters, the primary method of digestion involves the fermentation of fiber within an enlarged colon. This process is significant because colon fermenters, such as horses and rabbits, have evolved to maximize the extraction of nutrients from fibrous plant material. The enlarged colon serves as a fermentation chamber where a diverse community of microorganisms breaks down cellulose and other complex carbohydrates through fermentation. This fermentation process produces volatile fatty acids, which can then be absorbed by the animal and utilized as a primary energy source. This method is particularly efficient for herbivores that consume large amounts of plant material, enabling them to benefit from nutrients that would otherwise be unavailable if digestion were limited to enzymes alone. In contrast to other methods, such as enzyme digestion or absorption in the small intestine, colon fermentation allows for a more thorough utilization of the fibrous diet typical of these animals.